Object.prototype.getType = function () {
    return Object.prototype.toString.call(this).toLowerCase().slice(8, -1)
}

console.log(Number(123).getType())
console.log(Boolean(false).getType())
console.log('djfajl'.getType())
let t1 = []; console.log(t1.getType())
let t2 = Date(); console.log(t2.getType())
let t3 = function () { }; console.log(t3.getType())


let f1 = function (obj) {
    return Object.prototype.toString.call(obj).toLowerCase().slice(8, -1)
}

console.log(f1([]))


